Electrokinetic remediation is an emerging technology for the remediation of organic contaminated soil. In the existing electrokinetic remediation process, paired electrodes are inserted into contaminated soil, and a weak direct current is applied to form an electric field. Under the combined action of electrochemical reactions and electrokinetic effects, organic pollutants in soil are effectively removed.
In the previous study process, M×N matrix electrodes are arranged in an iso-spacing grid, and by the periodic polarity switching between the positive electrode and the negative electrode, a uniform electric field implementing full coverage is formed (CN 102294350 B). However, since the spatial distribution of the concentration of the organic pollutants in soil has heterogeneity, and the degradation efficiency is related to the electric field intensity, great spatial variability of the residual amount after pollutant remediation will be caused under the condition of the uniform electric field, so that the overall remediation efficiency of organic contaminated soil cannot reach a set standard.
Therefore, regarding to the contradiction of consistency between the heterogeneity of the spatial distribution of the organic pollutants in soil and the removal efficiency of the uniform electric field, the method of constructing the non-uniform electric field by additionally setting auxiliary electrodes, setting the polarity and switching mode in the high pollutant concentration region can compensate the electric field intensity of the high pollutant concentration region, thereby avoiding the spatial difference of efficiency of electrokinetically remedying organic contaminated soil, and having great significance to improve the overall efficiency of electrokineticaliy remedying organic contaminated soil.